To angle are supplementary. measure of one angle is 56 degrees, what is the measure of the second angle

  124°

Step-by-step explanation:

Supplementary angles add to 180°.

  56° + second angle = 180°

Subtract 56° from both sides of the equation:

  second angle = 180° - 56° = 124°

step-by-step explanation:

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.